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Updated: Apr 9, 2026

Electrophysiological Methods to Assess Peripheral Pain Block in an Anesthetized Rat
Published on: November 21, 2025
Comparative Efficacy of Hematoma Block Versus Circumferential Block in Pain Management for Distal Radius Fracture
Natee Kalapukdee1,2, Patarapon Inthawong3, Jaruwat Vechasilp2
1Ladyao Hospital, 1 moo 8, Nakhon Sawan, 60150, Thailand.
Background:
Distal radius fractures are among the most common orthopedic injuries requiring effective pain management during closed reduction. While the hematoma block is widely used, circumferential block has been proposed as an alternative due to its broader analgesic coverage. However, direct comparative evidence remains limited.
Methods:
This double-blind randomized controlled trial (RCT) included 51 patients with distal radius fractures treated from June 2023 to May 2024. Patients were randomized into hematoma block or circumferential block groups. Pain levels were measured using the Visual Analog Scale (VAS) at four time points: before injection, 5 min post-injection, during reduction, and 10 min post-reduction. Radiographic alignment and complications were also assessed.
Results:
Baseline characteristics were comparable between groups (p = 0.42). Pain scores were significantly lower in the circumferential block group across all post-injection time points (p < 0.01). VAS scores: Circumferential block provided better pain relief at 5 min post-injection (1.19 vs. 3.08), during reduction (1.61 vs. 4.96), and 10 min post-reduction (1.50 vs. 4.12). Radiographic alignment outcomes were similar between groups. No adverse events (e.g., neurovascular injury, infection) were reported.
Conclusions:
Circumferential block demonstrated superior pain control compared to hematoma block without compromising fracture alignment or increasing complications. Its broader periosteal innervation coverage and ease of administration suggest it may be a valuable alternative for pain management in distal radius fracture reduction. However, further studies with larger sample sizes and long-term functional assessments are warranted to confirm these findings.
Level Of Evidence I:
This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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